Finnish forestry professor Annika Kangas wrote in a column for a forestry magazine about two eye-opening cases, neither of which brings credit to research in the field.
According to her, an international research group in 2020 claimed (in this publication), based on satellite image analysis, that the area of forest logging in Europe had increased significantly. In Finland, the increase was allegedly 54 percent, and in Sweden, 36 percent. Furthermore, the biomass removed was estimated to have increased by up to 69 percent.
However, statistics from the same period indicated that the average logging area in Finland had only increased by 7.6 percent between 2016 and 2018 compared to the years 2011–2015, and the volume removed had increased by 13.8 percent. In Sweden, logging had even decreased.
When this data was compared in detail with official forest inventory data from Finland and Sweden, it became evident that advancements in remote sensing technology had significantly improved the probability of detecting logging during the observed period. The large increase in biomass removal, on the other hand, stemmed from a misinterpretation: the assumption that biomass is entirely removed in thinnings—an incorrect assumption.
The analysis relied on readily available global datasets that describe changes in forest canopy cover over time. However, these datasets do not allow for distinguishing between natural disturbances, thinnings, clear-cuttings, or even permanent deforestation.
This was information that the researchers who published these erroneous results should have been aware of. Or at the very least, they and other researchers working with remote sensing data should know by now; yet these same time series continue to be used in other studies, such as those modeling the impact of logging on certain bird species, for which they are entirely unsuitable.
Then, last summer, another claim was introduced (I could not identify the original report Kangas was referring to), asserting that the area of forests with trees at least 15 meters tall had significantly decreased in Europe. The largest decrease—about 20 percent—was again said to have occurred in Finland and Sweden.
This, however, is untrue. According to extensive field measurements, the area of such forests had actually increased during the observed period—by 25 percent in Sweden and by 35 percent in Finland. No explanation has been found for these errors, but they share a common feature with the earlier study: they rely solely on remote sensing. Field measurements were not conducted, nor were the remote sensing results validated on the ground.
This highlights the intense competition for research funding, which demands the production and rapid publication of new findings in large quantities. This competition often leads to the hasty adoption of new, modern methods, without first establishing whether these methods are truly suitable for the intended purpose.
In the worst cases, this rush can result in disasters like those described above, which may—even after corrections have been made—leave the general public and policymakers with an incorrect impression. For example, I have repeatedly encountered claims on social media suggesting that large trees are declining in Finland—a misconception likely fueled by the second study discussed here and the associated reporting before corrections were made.
Previous thoughts on the same topic:
The Finnish forest is life-threatening to asylum-seekers
Why are boreal forest fires on the rise everywhere but in Finland?
A new justification is needed for environmental activists
